The present invention relates generally to a tip and adapter assembly for an earthworking bucket and the like and, more particularly, to a novel interface between a tip adapter carried on the bucket and a bucket tip.
Earthworking implements, such as buckets for loaders and excavators commonly employ replaceable tips or teeth that engage the earth being worked or materials being excavated or loaded. Because of the highly abrasive materials encountered, bucket tips wear out rapidly and need to be replaced in order to protect the parent material of the bucket and to keep the bucket working at peak efficiency. Bucket tips are typically mounted on mounting structures referred to as tip adapters and are frequently subjected to high impact and prying forces that must be transferred from the tip into the adapter. To accomplish this, the adapter has a mounting nose that is received into a socket cavity of the tip. However if the forces acting on the tip become so great as to cause either the tip or adapter to break, it is more desirable to have the tip break, rather than the adapter as the adapter is more costly and more time consuming to replace.
The forces and impact loads on the tip also cause wear between the mating surfaces between the socket cavity of the tip and the mounting nose of the adapter. Therefore, its also desirable to provide a tip/adapter interface with adequate load carrying surfaces to minimize such wear and to extend the usable life of both the tip and adapter as a result of such wear.
While it is desirable to minimize such wear on the adapter, it cannot be completely eliminated. In addition, such wear is not readily apparent as the adapter nose is hidden from view due to being encased within the socket cavity of the tip. If too much wear occurs on the interface surfaces, the tip becomes exceedingly loose and wear between the tip and adapter interface surfaces accelerates and frequently results in premature tip failure or the loss of the tip from the adapter. Consequently, is also advantageous to be able to visually determine when the contacting interface surfaces of the adapter become worn to a point that replacement of the adapter is desirable to prevent the premature failure of the tip or its loss.
Because tips are quite frequently replaced due to rapid external wear, it is desirable to be able to quickly and easily remove the worn tip and replace it with a new one. Many types of retention devices, such as pins and the like, have been used in the past to retain the tip onto the adapter. Some typical examples of retention devices used for retaining bucket teeth are disclosed in U.S. Pat. No. 5,068,986 issued Dec. 3, 1991 to Larren F. Jones for Excavating Tooth Point Particularly Suited for Large Dragline Buckets; U.S. Pat. No. 5,272,824 issued Dec. 28, 1993 to Erwin D. Cornelius for Tooth Assembly with Leaf Spring Retainer; and U.S. Pat. No. 5,423,138 issued Jun. 13, 1995 to Richard E. Livesay, et al for Tip to Adapter Interface.
Many such prior retention devices perform satisfactorily, but are either complex and expensive, or require special tools or the large exertion of effort to remove and replace the retainers. Other retainers may simply fail during use do the high loads exerted on such retainers during use, resulting in the loss of the tool from the implement. It is therefore highly advantageous to use a hammerless type of retainer. One such hammerless retainer is the compression spring retainer disclosed in U.S. Pat. No. 5,937,549, issued May 19, 1997 to John L. Bender et al and assigned to the assignee hereof.
The present invention is directed to overcoming one or more of the problems encountered in the use of prior art tools and retention devices.
In accordance with one aspect of the present invention, a tip and adapter assembly is provided for an earthworking bucket that includes an elongated adapter and a replaceable tip. The adapter has a rear mounting portion adapted for mounting the adapter to the bucket and a front tip mounting nose for receiving a bucket tip. The tip mounting nose has a top surface, a bottom surface and a pair of side surfaces, each of the top and bottom surfaces having a longitudinally extending, centrally disposed rib protruding therefrom. Each of the side surfaces have a centrally located ear protruding therefrom. The replaceable tip has an elongated body disposed along a longitudinal axis and tapering from a wide rearward mounting end portion to a narrow forward ground engaging end portion. The mounting end portion has a rearwardly opening socket cavity for receiving the front tip mounting nose of the adapter. The socket cavity has pair of side walls, a top wall and a bottom wall. The top and bottom walls each have a central, longitudinally disposed recessed groove therein for receiving a respective one of the ribs of the adapter. Each of the side walls has a notch therethrough adapted to receive a respective one of the ears of the adapter.
In another aspect of the present invention, a replaceable bucket tip is adapted to be detachably mounted to a mounting nose of a bucket adapter by means of a retainer. The replaceable bucket tip includes an elongated body disposed along a longitudinal axis and tapering from a wide rearward mounting end portion to a narrow forward ground engaging end portion. The mounting end portion has a rearwardly opening socket cavity having a rectangularly shaped open end. The cavity is defined by pair of side walls, a top wall and a bottom wall. Each of the top and bottom walls have a central, longitudinally disposed recessed groove therein, and each of the side walls are generally parallel to each other and each have a notch extending forward from the open end toward the ground engaging end. The notch has a length sufficient to weaken the tip so as act as a fuse whereby before a vertical force acting upon the ground engaging end portion of the tip that would be sufficient to cause the breaking of the adapter on which the tip is mounted will result in the breakage of the tip first.